1. Field of the Invention
The invention relates to a water mixing faucet or fitting, in particular, a single control fitting of a temperature sensing means, operably coupled to the water outlet to display the temperature of the water being discharged.
2. Description of the Prior Art
Single control fittings are known, such as is used for wash basins, bathtubs, showers and bidets. They are designed to mix water flowing from the hot and/or cold water inlets, which are coupled to a mixing chamber so that the water being discharged is at the desired temperature. In order to ascertain the temperature of the mixed water and to avoid scalding, single control fittings of this type also include a temperature indicater operably coupled to a temperature measuring circuit.
In the past, fittings of this type having separate valve assemblies for hot and cold water and which are coupled to a discharge outlet to control wate r temperature, are known. Also, the single control fittings of the present type have become the fitting of choice. In a single control fitting, the temperature of the water being discharged is determined by shifting a lever which positions a valving element partially over the water inlet and outlet openings. The mixing fittings heretofore employed are shown in German patent DE-OS No. 30 45 531, FIGS. 1 to 4 and 7 through 8, respectively.
The temperature sensor shown, is a resistance sensor which projects into the free space of the mixed water outlet. The temperature sensor is connected, via connecting leads to the temperature measuring circuit, which is located at the rear of the water mixer fitting. The temperature measuring circuit includes a bridge circuit by which the desired temperature of the mixed water can be set. The element which visually displays the water temperature lights up whenever the temperature of the mixed water either increases or decreases from the desired setting.
In the known previously described water mixer fitting, the temperature measuring circuit has as its power source, a battery or an accumulator. The terms battery and accumulator, as used in this application, refer to a battery as a primary element that cannot be recharged and an accumulator as a secondary element that can be recharged. The temperature measuring circuit is switched on only when the water mixer fitting is in operation in order to keep power usage as low as possible. The measuring circuit is energized by means of a flow sensor which is positioned in the outlet of the water mixer fitting, cf FIG. 1 in DE-OS No. 30 45 531. The temperature indicator is activated through the temperature measuring circuit only when the rate of flow through the water outlet is sufficient.
In another water mixer fitting of the type described above, an electromechanical switch for each actuating element is used to switch the temperature measuring circuit on and off, cf U.S. Pat. No. 4,406,398, so that it is energized only when an actuating element is turned to its open position. Even with the power saving features provided by the design of the mixer fitting, frequent changing of the battery or frequent recharging of the accumulator is required. The overall construction requires relatively extensive changes to the water mixer fitting, particularly to water outlet design. The temperature indicator of this water mixer fitting is not particularly suitable for normal applications and, therefore, the above described water mixer fitting is not suitable for widespread use.